We conducted this study to evaluate the outcome of
203 patients admitted to PICU, using PRISM score. Overall mortality was
16.7%. The mean PRISM score was 6.5±3.6 and 15.5±7 for survivors and non
survivors, respectively (OR: 1.36; 95% CI=1.24–1.5; P<0.001).
PRISM score also correlated well with length of hospital stay and the
number of organ failures (P<0.001). A cut off score of 15 was
associated with 89.2% accuracy. PRISM score is highly sensitive in
predicting the outcome of pediatric patients in an ICU setting.

Keywords: ICU, Mortality, Outcome, PRISM score.

P

ediatric risk of mortality (PRISM)
score is considered to be the most effective in predicting the risk of
mortality(1-3). Data on the validity of PRISM outside USA and Europe is
limited, especially in developing countries (1,2,4-6). We conducted this
study to evaluate the sensitivity of PRISM score in predicting the outcome
of patients admitted to a PICU, in India.

Methods

Data were collected from a 12 bedded PICU of a tertiary
care hospital between March 2004 to February 2005, after the approval from
Institutional review board. Informed consent was obtained from the
parents. At admission, PRISM score was calculated(7) for all the patients
meeting the selection criteria, after a detailed history and examination
for the primary system affected and the number of organ failures. Children
with congenital malformations, less than one month of age, less than one
hour of hospital stay and patients discharged against medical advice in
whom the outcome was not known were excluded. Blood pressure was recorded
using non-invasive blood pressure monitor and oxygen saturation with a
pulse oximeter. The FiO2 required to
maintain oxygen saturation above 90% was noted with oxygen monitor.
Arterialized capillary heel prick blood was used for determining PaO2,
PaCO2 and bicarbonate. Standard laboratory techniques were utilized to
estimate total bilirubin, potassium, calcium, glucose, prothrombin time
and partial thromboplastin time. The clinical assessment of heart rate,
respiratory rate and pupillary reaction and the Glasgow Coma score were
noted by the resident doctor. The patients were followed up during the
hospital stay and the outcome measures were recorded as died or survived
at the end of the hospital stay. The results were analyzed applying
appropriate statistical tests.

Results

A total of 203 out of 222 admissions to PICU were
analyzed meeting the selection criteria. Overall, 16.7% children died.
Non-survivors had significantly more number of organ failures at admission
compared to survivors (1.5±0.9 vs 0.2±0.5; P<0.001) The mean
duration of hospital stay was more in survivors (6.5±3.4 vs 3.3±3.1
d; P<0.001).The proportion of the deaths was 5.3% with PRISM score
of 1-9 and increased to 100% with scores of 20-29 (Table I).
The mean PRISM scores were lower in survivors (6.5±3.6 vs 15.5±7;
P<0.001). Among the variables affecting the outcome, only the
number of organ failures had a moderate correlation with PRISM score (r=0.586,
P<0.001).With an increase in PRISM score by 1, the child’s
odds of death increased by 36% (OR 1.36, 95% CI=1.24-1.5). There was no
difference between the observed and expected outcome (P=0.63) using
the goodness of prediction model, suggesting a highly significant
prediction by PRISM score. This was confirmed by the logistic model with
89.2% of patients correctly classified. This suggests prediction of the
mortality by PRISM scores is valid and reliable.

TABLE IProbability of Death vs Prism Score

PRISM score

Probability of death (%)

5

4%

10

16%

15

48%

20

81%

25

95%

30

99%

Discussion

In this study, PRISM score was associated with an
increase in the mortality, with 89.2% accuracy with the cut off point of
15. The prediction of probalities of death using PRISM score in our study
showed the probability of death increases significantly with increase in
PRISM score and there was no significant difference between the observed
and the predicted outcomes, suggesting PRISM score to be a sensitive
predictor of outcome. This was comparable to other studies(1,2). The major
limitation of this study was a small sample size. Regular use of scoring
systems in PICU provides an opportunity not only to predict the outcome
but also helps in improvement of the quality of care within the limited
resources available.

Contributors: RB planned the study, performed
literature review, analyzed the data, drafted the manuscript and will act
as the guarantor. SR collected and analyzed the data, VDP and NSM
critically reviewed the manuscript.

Funding: None.

Competing interests:None stated.

What This Study Adds?

• PRISM score is sensitive in predicting the outcome of pediatric
in an ICU setting.